package cn.xuewei.pachong;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class URLPool {
    public static void main(String[] args) {
        getUrl("https://nipic.com/");
    }
    private static void getUrl(String basseUrl) {
        Map<String,Boolean> oldMap = new LinkedHashMap<String,Boolean>();
        String oldLinkHost = "";
        Pattern p = Pattern.compile("(http?://)?[^/\\s]*");
        Matcher m = p.matcher(basseUrl);
        if(m.find()){
            oldLinkHost = m.group();
        }
        oldMap.put(basseUrl,false);
        oldMap = crawlLinks(oldLinkHost,oldMap);
        for(Map.Entry<String,Boolean> mapping : oldMap.entrySet()){
            System.out.println("链接："+mapping.getKey());
        }

    }
    private static Map<String,Boolean> crawlLinks(String oldLinkHost,Map<String,Boolean> oldMap){
        Map<String,Boolean> newMap = new LinkedHashMap<String,Boolean>();
        String oldLink = "";
        for(Map.Entry<String,Boolean> mapping : oldMap.entrySet()) {
            System.out.println("链接："+mapping.getKey()+"---check:"+mapping.getValue());
            if (!mapping.getValue()) {
            }
            oldLink = mapping.getKey();
            try {
                URL url = new URL(oldLink);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setRequestMethod("GET");
                if (connection.getResponseCode() == 200) {
                    BufferedReader reader = new BufferedReader(
                            new InputStreamReader(connection.getInputStream())
                    );
                    Pattern p = Pattern.compile("<a.*?href=[\"']?((https?://)?/?[^\"']+)[^\"']?.*?>(.+)</a>");
                    Matcher matcher = null;
                    String line = "";
                    while ((line = reader.readLine()) != null) {
                        matcher = p.matcher(line);
                        if (matcher.find()) {
                            String newLink = matcher.group(1).trim();
                            if (!newLink.startsWith("http")) {
                                if (newLink.startsWith("/")) {
                                    newLink = oldLinkHost + newLink;
                                } else {
                                    newLink = oldLinkHost + "/" + newLink;
                                }
                            }
                            if (newLink.endsWith("/")) {
                                newLink = newLink.substring(0, newLink.length() - 1);
                            }
                            if (!oldMap.containsKey(newLink)
                                    && !newMap.containsKey(newLink)
                                    && newLink.startsWith(oldLinkHost)) {
                                newMap.put(newLink, false);
                            }
                        }
                    }
                }
            } catch (Exception e) {

            }
            oldMap.replace(oldLink,false,true);
        }
        if (!newMap.isEmpty()){
            oldMap.putAll(newMap);
            oldMap.putAll(crawlLinks(oldLinkHost, oldMap));
        }
        return oldMap;
        }
    }

